Living body tissue harvesting apparatus

ABSTRACT

In an apparatus to harvest a living body tissue, in order to prevent pressure in a body cavity exceeding a predetermined value, a living body tissue harvesting apparatus according to the present invention has a grip section and an insertion section to be inserted into the body cavity. Further, in order to discharge a predetermined gas from an opening part provided on the insertion section, the living body tissue harvesting apparatus has a gas supplying tube for supplying the predetermined gas into the insertion section, and a space for releasing the predetermined gas supplied into the body cavity.

CROSS REFERENCES TO RELATED APPLICATIONS

This application is a continuation application of PCT/JP2005/017491filed on Sep. 22, 2005 and claims benefit of Japanese PatentApplications No. 2004-275747 filed in Japan on Sep. 22, 2004 and No.2004-275752 filed in Japan on Sep. 22, 2004, the entire contents ofwhich are incorporated herein by this reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a living body tissue harvestingapparatus for harvesting living body tissues such as a subcutaneousvessel.

2. Description of the Related Art

In a bypass surgery of a blood vessel of heart, as the blood vessel forbypass, a subcutaneous vessel such as a great saphenous vein isoccasionally used. Conventionally, in the operation, in order to seeentire blood vessel from an inguinal region in lower limb to an ankle,skin in the lower limb is cut and the subcutaneous vessel is extracted.In recent years, an operation is performed wherein a subcutaneous vesselsuch as a great saphenous vein is pulled and harvested under endoscopicobservation.

For example, U.S. Pat. No. 5,895,353 and Japanese Unexamined PatentApplication Publication No. 2004-008241 disclose instruments used insuch operations under endoscopic observation.

These instruments are composed of instruments such as a dissector,harvester, or the like. Through the dissector and harvester, anendoscope can be inserted, and an operator can harvest the blood vesselwhile watching the endoscopic image.

The dissector is an instrument which is inserted from a trocar which isa guiding tube set to an incision part in the vicinity below a patient'sknee, by being inserted through the entire length of the blood vessel tobe harvested, gradually dissects the blood vessel and the peripheraltissues.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a living body tissueharvesting apparatus having a grip section and a tubular insertionsection connected to the grip section and to be inserted into a bodycavity. The living body tissue harvesting apparatus includes a gassupplying path for supplying a predetermined gas from an external gassupplying device into the insertion section, a first opening partprovided on the insertion section for discharging the predetermined gasfrom the gas supplying path through the insertion section, and acommunication path provided in the insertion section for communicatingwith outside through the grip section.

According to the living body tissue harvesting apparatus of the presentinvention, pressure in the body cavity is prevented from becoming abovea predetermined value.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a structural view illustrating a structure of a surgery systemaccording to a first embodiment of the present invention;

FIG. 2 is a perspective view illustrating a trocar according to thefirst embodiment of the present invention;

FIG. 3 is a longitudinal sectional view illustrating the trocaraccording to the first embodiment of the present invention;

FIG. 4 is a flowchart for explaining an operating method of pulling asubcutaneous vessel and harvesting the pulled subcutaneous vessel;

FIG. 5 is an illustration for explaining the operating method of pullinga subcutaneous vessel and harvesting the pulled subcutaneous vessel;

FIG. 6 is a cross-sectional view illustrating a state in which adissector is inserted into subcutaneous of lower limb through a trocaraccording to the first embodiment of the present invention;

FIG. 7 is an illustration for explaining an operating method of pullinga subcutaneous vessel and harvesting the pulled subcutaneous vessel;

FIG. 8 is a cross-sectional view illustrating a state in which aharvester is inserted into subcutaneous of lower limb from an incisionpart through the trocar;

FIG. 9 is an illustration for explaining an operating method of pullinga subcutaneous vessel and harvesting the pulled subcutaneous vessel;

FIG. 10 is a side view of the dissector according to the firstembodiment of the present invention;

FIG. 11 is a partial cross-sectional view of the dissector according tothe first embodiment of the present invention;

FIG. 12 is a cross-sectional view taken along the line A-line A of FIG.11 according to the first embodiment of the present invention;

FIG. 13 is a cross-sectional view taken along the line B-line B of FIG.11 according to the first embodiment of the present invention;

FIG. 14 is a cross-sectional view taken along the line C-line C of FIG.11 according to the first embodiment of the present invention;

FIG. 15 is a partial perspective view of the base end side of thedissector according to the first embodiment of the present invention;

FIG. 16 is a partial cross-sectional view of the tip side of a gripsection according to the first embodiment of the present invention;

FIG. 17 is a perspective view of a harvester according to the firstembodiment of the present invention;

FIG. 18 is a partial perspective view for explaining a structure of thebase end side of the harvester according to the first embodiment of thepresent invention;

FIG. 19 is a partial perspective view showing a structure of the tipside of the harvester according to the first embodiment of the presentinvention;

FIG. 20 is an illustration for explaining operation of a lock axis ofFIG. 19;

FIG. 21 is an illustration viewed from the direction of the arrow A ofFIG. 19;

FIG. 22 is a cross-sectional view in the direction of the long axisillustrating an operating structure of the harvester according to thefirst embodiment of the present invention;

FIG. 23 is a conceptual view of an attachment of a vein keeper leverviewed from the direction of the arrow B of FIG. 22;

FIG. 24 is a cross-sectional view in the direction of the long axisillustrating a structure for supplying gas of the harvester according tothe first embodiment of the present invention;

FIG. 25 is a cross-sectional view taken along the line D-line D of FIG.24;

FIG. 26 is a first illustration for explaining operation of a veinkeeper of the harvester according to the first embodiment of the presentinvention;

FIG. 27 is a second illustration for explaining operation of the veinkeeper of the harvester according to the first embodiment of the presentinvention;

FIG. 28 is a third illustration for explaining operation of the veinkeeper of the harvester according to the first embodiment of the presentinvention;

FIG. 29 is an illustration of a bipolar cutter viewed from the topsurface of the tip part of the bipolar cutter according to the firstembodiment of the present invention;

FIG. 30 is a cross-sectional view of the bipolar cutter of FIG. 29;

FIG. 31 is an exploded perspective view of a tip part of a modifiedbipolar cutter;

FIG. 32 is an illustration of the bipolar cutter viewed from the topsurface according to the first embodiment of the present invention;

FIG. 33 is an illustration of the bipolar cutter viewed from the undersurface according to the first embodiment of the present invention;

FIG. 34 is a cross-sectional view of the bipolar cutter taken along theline E-line E of FIG. 32;

FIG. 35 is a cross-sectional view of the bipolar cutter taken along theline F-line F of FIG. 32;

FIG. 36 is an illustration of a tissue holding part viewed from theunder surface according to the first embodiment of the presentinvention;

FIG. 37 is a cross-sectional view of the tissue holding part taken alongthe line G-line G of FIG. 36 according to the first embodiment of thepresent invention;

FIG. 38 is a cross-sectional view of the tissue holding part taken alongthe line H-line H of FIG. 36 according to the first embodiment of thepresent invention;

FIG. 39 is an illustration for explaining cutting operation of a branchwith the bipolar cutter according to the first embodiment of the presentinvention;

FIG. 40 is an illustration for explaining the cutting operation of thebranch with the bipolar cutter according to the first embodiment of thepresent invention;

FIG. 41 illustrates the tissue holding part viewed from the undersurface at a time of cutting the branch.

FIG. 42 illustrates an external appearance of a disposable dissectoraccording to the first embodiment of the present invention;

FIG. 43 illustrates an external appearance of a disposable harvesteraccording to the first embodiment of the present invention;

FIG. 44 is a partial cross-sectional view of a tip part of an insertionsection according to a second embodiment of the present invention;

FIG. 45 is a partial cross-sectional view of a tip part of a gripsection according to the second embodiment of the present invention;

FIG. 46 is an illustration for explaining a position of an opening partof each hole in the insertion section according to the second embodimentof the present invention; and

FIG. 47 is a partial cross-sectional view of a dissector according to athird embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment

An embodiment of the invention will be described below with reference toFIG. 1 through FIG. 43.

FIG. 1 through FIG. 43 relate to a surgery system in which asubcutaneous vessel is pulled and harvested according to the embodimentof the present invention. FIG. 1 is a structural view illustrating astructure of a surgery system. FIG. 2 is a perspective view illustratinga trocar. FIG. 3 is a longitudinal sectional view illustrating thetrocar. FIG. 4 is a flowchart for explaining an operating method ofpulling a subcutaneous vessel and harvesting the pulled subcutaneousvessel. FIG. 5 is an illustration for explaining the operating method ofpulling a subcutaneous vessel and harvesting the pulled subcutaneousvessel. FIG. 6 is a cross-sectional view illustrating a state in which adissector is inserted into subcutaneous of lower limb through a trocar.FIG. 7 is an illustration for explaining an operating method of pullinga subcutaneous vessel and harvesting the pulled subcutaneous vessel.FIG. 8 is a cross-sectional view illustrating a state in which aharvester is inserted into subcutaneous of lower limb from an incisionpart through the trocar. FIG. 9 is an illustration for explaining anoperating method of pulling a subcutaneous vessel and harvesting thepulled subcutaneous vessel. FIG. 10 is a side view of the dissector.FIG. 11 is a partial cross-sectional view of the dissector. FIG. 12 is across-sectional view taken along the line A-line A of FIG. 11. FIG. 13is a cross-sectional view taken along the line B-line B of FIG. 11. FIG.14 is a cross-sectional view taken along the line C-line C of FIG. 11.FIG. 15 is a partial perspective view of the base end side of thedissector. FIG. 16 is a partial cross-sectional view of the tip side ofa grip section. FIG. 17 is a perspective view of a harvester. FIG. 18 isa partial perspective view for explaining a structure of the base endside of the harvester. FIG. 19 is a partial perspective view showing astructure of the tip side of the harvester. FIG. 20 is an illustrationfor explaining operation of a lock axis shown of 19. FIG. 21 is anillustration viewed from the direction of the arrow A in FIG. 19. FIG.22 is a cross-sectional view in the direction of the long axisillustrating an operating structure of the harvester. FIG. 23 is aconceptual view of an attachment of a vein keeper lever viewed from thedirection of the arrow A of FIG. 22. FIG. 24 is a cross-sectional viewin the direction of the long axis illustrating a structure for supplyinggas of the harvester. FIG. 25 is a cross-sectional view taken along theline D-line D of FIG. 24. FIG. 26 is a first illustration for explainingoperation of a vein keeper. FIG. 27 is a second illustration forexplaining operation of the vein keeper. FIG. 28 is a third illustrationfor explaining operation of the vein keeper. FIG. 29 is an illustrationof a bipolar cutter viewed from the top surface of the tip part of thebipolar cutter. FIG. 30 is a cross-sectional view of the bipolar cutterof FIG. 29. FIG. 31 is an exploded perspective view of a tip part of amodified bipolar cutter. FIG. 32 is an illustration of the bipolarcutter viewed from the top surface. FIG. 33 is an illustration of thebipolar cutter viewed from the under surface. FIG. 34 is across-sectional view of the bipolar cutter taken along the line E-line Eof FIG. 32. FIG. 35 is a cross-sectional view of the bipolar cuttertaken along the line F-line F of FIG. 32. FIG. 36 is an illustration ofa tissue holding part viewed from the under surface. FIG. 37 is across-sectional view of the tissue holding part taken along the lineG-line G of FIG. 36. FIG. 38 is a cross-sectional view of the tissueholding part taken along the line H-line H of FIG. 36. FIG. 39 is anillustration for explaining cutting operation of a branch with amodified bipolar cutter. FIG. 40 is an illustration for explaining thecutting operation of the branch with a modified bipolar cutter. FIG. 41illustrates the tissue holding part viewed from the under surface at atime of cutting the branch. FIG. 42 illustrates an external appearanceof a disposable dissector. FIG. 43 illustrates an external appearance ofa disposable harvester.

First, with reference to FIG. 1 through FIG. 6, a system for pulling andharvesting a subcutaneous vessel as a living body tissue, and anoperating method for harvesting a blood vessel using a living bodyharvesting surgery system will be described.

As shown in FIG. 1, a living body harvesting surgery system (hereinaftermay be referred to as surgery system) 101 includes a trocar 21, adissector 31, a harvester 41 and a rigid endoscope 51 which is aendoscope. The dissector 31 and the harvester 41 are living body tissueharvesting devices. The surgery system 101 further includes a televisionmonitor 102, which is a display device, a camera control unit(hereinafter referred to as CCU) 103, a television camera device 104, alight source device 105, a light guide cable 106, an electric knifedevice 107, and a gas supplying device 108.

To a light guide connector part 52 of the rigid endoscope 51, an end ofthe light guide cable 106 is connected. The other end of the light guidecable 106 is connected to the light source device 105. To the rigidendoscope 51, light from the light source device 105 is provided throughthe light guide cable 106 into which a light guide of optical fiber isinserted, and a subject is illuminated from the tip part of the rigidendoscope 51. A camera head part of the television camera device 104 isconnected to an eyepiece part 53 of a base end side of the rigidendoscope 51. The television camera device 104 is connected to the CCU103, and an image of the subject obtained by the rigid endoscope 51 isdisplayed on a screen of the television monitor 102.

A tip insertion section 54 of the rigid endoscope 51 can be insertedinto a rigid endoscope insertion channel 36 from a base end side of thedissector 31 which is the living body tissue harvesting device.Similarly, the tip insertion section 54 of the rigid endoscope 51 can beinserted into a rigid endoscope insertion channel 46 of the harvester 41which is the living body tissue harvesting device from a base end sideof the harvester 41. The rigid endoscope insertion channels 36 and 46are mounting parts for mounting the endoscope 51 to the insertionsection of the dissector 31 and the harvester 41 respectively, andconstitute endoscope insertion means.

A gas supplying tube 34 of the dissector 31 is connected to the gassupplying device 108, a predetermined gas, for example, carbon dioxidegas, is supplied from the gas supplying device 108, and the gas isdischarged from an opening 35 a (not shown in FIG. 1) which is a gassupplying outlet of the insertion section.

A gas supplying tube 44 of the harvester 41 is also connected to the gassupplying device 108, a predetermined gas, for example, carbon dioxidegas, is supplied from the gas supplying device 108, and the gas isdischarged from an opening (not shown in FIG. 1) which is a gassupplying outlet of the insertion section. The gas supplying tubes 34and 44 respectively constitute gas supplying means inside of theinsertion sections of the dissector 31 and the harvester 41.

The harvester 41 has an electrical cable 47 for the bipolar cutter 43(not shown in FIG. 1). The harvester 41 is connected to the electricknife device 107 by a connector provided at a base end side of theelectrical cable 47. By using the surgery system 101 having thestructure, as will be described below, the operator can perform anoperation in which a subcutaneous vessel as a target living body tissueto be harvested is pulled and harvested. First, by using the dissector31, circumferential tissues of great saphenous vein (hereinafter may bereferred to as blood vessel) from a thigh of a lower limb to an ankle isdissected, and then, by using the harvester 41, peripheral branches arecut. After the operation is performed, the end part of the blood vesselis treated and the blood vessel is extracted. As described the above,under endoscopic observation, the living body tissues are harvested.

As shown in FIGS. 2 and 3, the trocar 21 includes a guiding tube part 22which is a guide sheath, a seal member 23, and a fixing part 24 forfixing the trocar 21 to the skin. The guiding tube part 22 has acylindrically-shaped hollow part 25 through which the insertion sections32 and 42 of the dissector 31 and the harvester 41 can be inserted. Thetip side of the guiding tube part 22 has a shape which is cut away at apredetermined angle, for example, an angle of forty-five degrees, to adirection orthogonal to the axis direction of the guiding tube 22. Thebase end side of the guiding tube part 22 has a shape which is cut awayin a direction orthogonal to the axis direction of the guiding tube 22.At the base end side of the guiding tube part 22, a seal member 23 isprovided. The seal member 23 is made of an elastic member, and has ahole 26 which has an inside diameter smaller than that of the guidingtube member 22. In the inner circumference of the hole 26, a convex part27 is provided at the tip side so that the inner diameter at the tip endside becomes smaller than that at the base end side. By thus shaped hole26, the insertion section 32 of the dissector 31 or the insertionsection 42 of the harvester 41 which is inserted into the guiding tubepart 22 can be held in an air-tight state under the skin.

On a peripheral surface of the guiding tube part 22 of the trocar 21, aclip member 29 which uses elastic force of a torsion spring 28 which isan elastic member, is provided. The clip member 29 has a plate shapeformed in a dogleg shape having a tip part 29 a and a base end part 29b. At substantially central part of the dogleg-shaped plate, the torsionspring 28 is provided.

By the torsion spring 28, the tip part 29 a of the clip member 29 isalways in a pressed state toward the peripheral surface of the guidingtube part 22. The tip part 29 a can be apart from the peripheral surfaceof the guiding tube part 22 by depressing the base end part 29 b of theclip member 29 against the pressure of the torsion spring 28. Thus, bydepressing the base end part 29 b of the clip member 29 toward the sideof the peripheral surface of the guiding tube part 22, it is possible tohold skin of a lower limb 12, or the like between the tip part 29 a ofthe clip member 29 and the peripheral surface of the guiding tube part22 (see FIGS. 6 and 8).

On the peripheral surface of the guiding tube part 22, a plurality ofcircularly round convex parts 22 a is provided. The convex part 22 a canbe provided by being integrally formed with the guiding tube part 22 orprovided as a different member from the guiding tube part 22. On theperipheral surface of the guiding tube part 22 of the tip part 29 a ofthe clip member 29, catching part 29 c is formed. Thus, as shown inFIGS. 6 and 8, in the state that the skin of the lower limb 12, or thelike is held between the tip part 29 a of the clip member 29 and theperipheral surface of the guiding tube part 22 by the pressure of thetorsion spring 28, the skin of the lower limb 12, or the like is tightlyheld and fixed by the catching part 29 c of the clip member 29 and theperipheral surface of the guiding tube part 22. Accordingly, thecatching part 29 c and the convex part 22 a of the guiding tube part 22constitute a fixation part 24 which has a so-called non-slip mechanism.

In the above-structured surgery system 101, in a bypass operation ofheart, it is possible to harvest the blood vessel to be used as aharvesting target tissue of the lower limb. With reference to FIG. 4through FIG. 9, a case in which an entire great saphenous vein(hereinafter, may be referred to as blood vessel), which is theharvesting target blood vessel used for bypass, is harvested from athigh of the lower limb to an ankle will be described. In theembodiment, according to an example of routine shown in the flowchart inFIG. 4, the above-described blood vessel harvesting operation using theliving body harvesting surgery system 101 will be described.

As shown in FIG. 5, a harvesting target blood vessel 11 exists betweenan inguinal region 13 of a lower limb 12 and an ankle 14. The length ofthe blood vessel 11 to be harvested is, for example, 60 cm.

First, the operator identify the position of the blood vessel 11 (step(hereinafter, referred to as S) 1). The position of the blood vessel 11is identified by a tactile impression of the operator or by using adevice such as sonar. Then, in a direction substantially along the tubeof the blood vessel 11, right above the identified blood vessel 11 andslightly below a knee 15, the operator provides an incision part 16, forexample, having the length of 2.5 cm, by a surgical knife, or the like(S2). Then, at the incision part 16, the blood vessel 11 is exposed andperipheral tissues of the blood vessel 11 are dissected (S3).

Next, by using the dissector 31, the peripheral tissues of the entirelength of the blood vessel 11 are dissected (S4). Specifically, theoperator sets the trocar 21 to the incision part 16, inserts thedissector 31 through a guiding tube part 22 of the trocar 21, whilewatching the endoscopic image, gradually inserts the dissector 31 fromthe incision part 16 in the direction to the inguinal region 13(indicated by the arrow A1), and bluntly dissects the blood vessel 11from the peripheral tissues. The endoscopic image is necessary for theoperator to dissect the peripheral tissues along the blood vessel 11.

When dissecting the peripheral tissues of the blood vessel 11, forexample, if it is considered that the direction of the skin surface fromthe blood vessel 11 is an upward direction, the operator can completelydissect the peripheral tissues from the entire circumference of theblood vessel 11 by dissecting in the upward and downward directions ofthe blood vessel 11, and further rightward and leftward directions ofthe blood vessel. By dissecting the entire circumference of the bloodvessel 11, it is possible for the operator to watch the branches of theblood vessel 11 more clearly in the endoscopic image.

When the dissecting of the blood vessel 11 from the peripheral tissuesin the inguinal region 13 direction is completed, the dissector 31 ispulled from the trocar 21. Then, the direction of the trocar at theincision part 16 is changed, and the dissector is gradually insertedfrom the incision part 16 in the direction to the ankle 14 (indicated bythe arrow A2), and the blood vessel 11 is dissected from the peripheraltissues while watching the endoscopic image.

As shown in FIG. 3, when the trocar 21 is set to the incision part 16,the operator inserts the guiding tube part 22 from the incision part 16in the direction to the inguinal region, and fixes to the skin by thefixing part 24. The insertion section 32 of the dissector 31 is insertedinto the subcutaneous of the lower limb 12 through the guiding tube part22 of the trocar 21 fixed to the incision part 16 by the fixing part 24.

As will be described below, an endoscope insertion section is insertedinto the insertion section 32. Since the insertion direction of thedissector 31 is along the direction of the blood vessel 11, the operatorgradually inserts the dissector 31 while watching the endoscopic imageso as to dissect the peripheral tissues of the blood vessel 11 from theblood vessel 11. That is, the insertion is not performed to directlyreach the inguinal region 13 from the incision part 16 along the bloodvessel 11. By moving the dissector 31 forward and backward along theinsertion direction, the dissectings of the blood vessel 11 is graduallyperformed to the inguinal region 13 and to the ankle 14.

Then, by a gas supplying connector provided to the dissector 31, apredetermined gas, for example, carbon dioxide gas, is supplied from agas supplying tube 34 connected to a grip section 33 of the dissector31, and blown out from an opening part 35 a provided at the tip part ofthe insertion section 32.

Accordingly, while the blood vessel 11 is dissected from the peripheraltissues, the predetermined gas, for example, carbon dioxide gas, existsbetween the dissected tissues and the blood vessel, and the operatingfield of the endoscope is broadened and the visibility is improved.Thus, the operator is able to perform the dissecting operation easily.

Then, the operator pulls the dissector 31 from the trocar 21, while thetrocar 21 is left, inserts the harvester 41 (see FIG. 8), and cuts thebranches of the blood vessel 11 from the incision part 16 to the ankle14 (S5).

When the operator cuts the branches 11A, first, inserts the harvester 41from the incision part 16 to below the ankle 14, and in the directionfrom the ankle 14 to the incision part 16, cuts the branches 11A one byone.

The cutting of the branches 11A is performed by using a bipolar cutter43 which is an electric knife provided at a tip part of the insertionsection 42 of the harvester 41. The cut part of the branches 11A cut bythe bipolar cutter 43 become substantially stanched state. By using theharvester 41, all of the branches 11A of the blood vessel 11 to theankle 14 are cut.

A structure of the harvester 41 will be described below in detail. Abrief structure will now be described. A vein keeper 45 is a bloodvessel holding part provided at the tip part of the harvester 41 to hookthe blood vessel 11. The vein keeper 45 of the harvester 41 has amechanism that when the operator hooks the blood vessel 11 to the veinkeeper 45, a part of the vein keeper 45 is opened and the blood vessel11 is hooked to the opened part, after the blood vessel 11 is hooked,the opened part is closed. Further, since the vein keeper 45 is movablein the axis direction of the harvester 41, and it is possible to movethe vein keeper 45 in the direction separating from the tip part of theendoscope, the hooked blood vessel 11 can be seen easier in theendoscopic image.

Further, at the tip part of the bipolar cutter 43, a groove of 0.5 mmwidth is formed. When the branch 11A is cut, the branch 11A is pushedinto the groove and cut in a compressed state. Moreover, at the tip partof the harvester 41, on the inside of surrounded part surrounded by awiper guard part, a wiper for wiping extraneous matters adhered on awindow part of the tip part of the rigid endoscope is provided. And, ona part of the cylindrical wiper guard, a sweeping hole for sweeping theextraneous matters wiped by the wiper is provided. As the extraneousmatters, blood, fat, smoke due to the electric knife or the like can beconsidered.

The harvester 41 is also provided with a gas supplying connector, carbondioxide gas is supplied from a gas supplying tube 44 connected to a gripsection 400 of the harvester 41, and blows out from an opening part (notshown) provided at the tip part of the insertion section 42.Accordingly, the cutting operation of the branches 11A becomes easier.

Since a plurality of the branches 11A exists in the blood vessel 11,while watching the endoscopic image at the tip of the insertion section42 of the harvester 41, the operator holds the blood vessel 11 byoperating the vein keeper 45 of the tip part of the harvester 41,confirms the branches 11A one by one, and cuts the branches 11A by thebipolar cutter 43. A structure of the vein keeper 45 will be describedbelow.

Then, a treatment of the distal end is performed by providing a smallincision part, for example, the length of the incision part is notgreater than 1 cm, on the ankle 14, the distal end of the blood vessel11 is pulled from the incision part 17, and the distal end is tied witha piece of string or indwelled with forceps (S6). In this case, theoperator inserts the harvester 41 near the incision part 16 again intothe subcutaneous of the ankle 14, and while watching the subcutaneousvessel 11 under the incision part 17 and the forceps by using theendoscope, pinches the blood vessel 11 with the forceps, and pulls theblood vessel 11 from the incision part 17.

FIG. 7 is an illustration for explaining the treatment of the distal endof blood vessel 11. The treatment of the distal end of blood vessel 11is performed by tying a part of the blood vessel 11 with a piece ofstring, and cutting the blood vessel 11 at a position 11 b which isnearer to knee 15 than the knot 11 a. The incision part at the incisionpart 17 is closed by the operator with a tape or the like.

In the treatments of the distal end of the blood vessel 11, the operatorpulls the blood vessel 11 from the incision part 17 while watching thesubcutaneous vessel under the incision part 17 by the endoscope.

Then, the harvester 41 is pulled from the trocar 21, the direction ofthe guiding tube part 22 of the trocar 21 in the incision part 16 ischanged to the direction to the inguinal region 13, the harvester 41 isinserted, and branches of the blood vessel 11 between the incision part16 and the inguinal region 13 are cut (S7). As performed in S6, theoperator cuts the branches 11A of the blood vessel 11 from the incisionpart 16 to the inguinal region 13 while watching the endoscopic image.

Also, the cutting operation of the branches 11A is performed byinserting the harvester 41 from the incision part 16 into under theinguinal region 13, from the inguinal region 13 toward the incision part16, the branches 11A of the blood vessel 11 are cut one by one.

As shown in FIG. 8, the insertion section 42 of the harvester 41 isinserted into the subcutaneous of the lower limb 12 through the guidingtube part 22 of trocar 21 fixed to the incision part 16 by the fixingpart 24. As will be described below, an endoscope insertion section isinserted into the insertion section 42. Since the insertion direction ofthe harvester 41 is along the direction of the blood vessel 11, theoperator cuts the branches 11A while watching the endoscopic image.

When the cutting operation of the branches 11A of the blood vessel 11 iscompleted, as shown in FIG. 7, the treatment of the distal end isperformed by providing a small incision part, for example, the length ofthe incision part is not greater than 1 cm, on the inguinal region 13,the distal end of the blood vessel 11 is pulled from the incision part18, and the distal end is tied with a piece of string or indwelled withforceps (S8).

Also in this case, the operator inserts the harvester 41 near theincision part 16 again into the subcutaneous of the inguinal region 13while watching the subcutaneous vessel 11 under the incision part 18 andthe forceps by the endoscope, pinches the blood vessel 11 with theforceps, and pulls the blood vessel 11 from the incision part 18.Similarly to the treatment at the incision part 17 of the ankle 14, thetreatment of the distal end of blood vessel 11 is performed by tying apart of the blood vessel 11 with a piece of string, and cutting theblood vessel 11 at a position 11 d which is nearer to knee 15 than theknot 11 c. The incision part at the incision part 18 is closed by theoperator with a tape or the like.

Then, as shown in FIG. 9 the operator extracts the blood vessel 11, forexample, the length is 60 cm, from the incision part 16 (S9). When theextraction of the blood vessel 11 is completed, then, the operatorperforms a leak check of the blood vessel 11 because if there is anopening on the extracted blood vessel 11, it is not possible to use theblood vessel 11 as a blood vessel to be used for a bypass (S10).

While performing the leak check, the operator ties all of the branches11A of the blood vessel 11 with a piece of string in order to preventthe cut distal end parts of the branches 11A from blood leaking. In thestate in which all of the branches 11A are tied with a piece of string,in consideration of the direction of valves in the blood vessel 11, asyringe is attached to an end of the blood vessel 11, physiologicalsaline is passed through in the blood vessel 11, and by checking whetherthere is an opening from which the physiological saline is leaking ornot, the operator performs the leak check of the blood vessel 11.

If there is an opening from which the physiological saline is leaking,the opening is stitched together (S11). Finally, the incision part 16 isstitched together (S12).

As described above, compared with a known operation in which tissues ofa certain part of the lower limb 12 are incised so that the entire bloodvessel 11 from the inguinal region 13 of the lower limb 12 to the ankle14 can be seen, the above-described method for extracting the bloodvessel by using the endoscope is minimally invasive to a patientbecause, for example, the incision parts are only three. It can bepossible, for example, to reduce the period of time required for thepatient to become able to walk after the operation.

Referring to FIG. 10 through FIG. 16, a structure of the dissector 31will be described. As shown in FIG. 5, the dissector 31 mainly includesan insertion section 32 and a grip section 33 connected to the insertionsection 32. At the tip part of the insertion section 32 which is made ofmetal, a dissecting member 37 is provided. The dissecting member 37 ismade of a material such as a transparent synthetic resin, and has acylindrical shape at the base end side and a cone shape at the tip side.Since the dissecting member 37 is a transparent member, whensubcutaneously inserted, it is possible to obtain an image of a subjectilluminated by light illuminated from the tip part of the rigidendoscope 51 inserted into a rigid endoscope insertion channel 36 byusing the rigid endoscope 51.

As shown in FIG. 11 through FIG. 14, along an axis direction of thedissector 31, a metal tube member 36 a which forms the rigid endoscopeinsertion channel 36 is inserted through the inside of the dissector 31from the base end of the grip section 33 to the tip part of theinsertion section 32. At the tip side of the grip section 33, asubstantially column-shaped first connecting member 38 is provided.Specifically, the grip section 33 is a hollow cylindrical outer member,and on the inner circumference surface of the outer member at the tipside of the grip section 33, the outer circumferential surface of thefirst connecting member 38 is contacted and fit through a sheath 39.

At an end surface 38 b of the base end side of the first connectingmember 38, the gas supplying tube 34 is connected. On the firstconnecting member 38, a hole 38 c which communicates an inside space ofthe gas supplying tube 34 with an inside space of the metal sheath 39 isformed. The hole 38 c is a communication path between the inside spaceof the gas supplying tube 34 and the inside space of the metal sheath39. An opening part 38 d of the hole 38 c is provided on the tip sidesurface of the first connecting member 38. That is, at an end of thehole 38 c, the gas tube 34 is fit in the grip section 33, another end ofthe hole 38 c is inside of the metal sheath 39, and opens within anoutside space 39 a of the tube member 36 a. At the base end of the gassupplying tube 34, a gas supplying connector 34 a is provided. The gassupplying connector 34 a is connected to a connector of a tube connectedto the gas supplying device 108. Thus, the gas supplying device 108 cansupply a predetermined gas in the sheath 39 through the gas supplyingtube 34 and the hole 38 c of the first connecting member 38.

The dissecting member 37 and the sheath 39 of the insertion section 32are connected by a second connecting member 58 a. The dissecting member37 fits at the tip side of the second connecting member 58 a, and thesheath 39 fits at the base end side of the second connecting member 58a. Accordingly, the insides of the dissecting member 37 and the sheath39 are combined together to be airtight.

At the base end side of the second connecting member 58 a, threehook-shaped parts 58 b which protrude toward the base end side areformed. The tip side of the hook-shaped part 58 b has a convex part 58 cextends in a direction radiating from the central axis in a planeorthogonal to the axis direction of the insertion section 32. On thesheath 39, holes 35 are formed at a position corresponding to each ofthe tip parts of the three hook-shaped parts 58 b. The hole 35 of thesheath 39 of the insertion section 32 is formed so as to catch theconvex part 58 c. Further, sizes of each convex part 58 c and hole 35are set to form a space between the hole 35 and the convex part 58 c inthe state that the convex part 58 c is caught in the hole 35. Thus,three openings 35 a are formed. An outer diameter of the secondconnecting member 58 a at the base end side is larger than that of thesheath 39.

Accordingly, the carbon dioxide gas supplied from the gas supplying tube34 is introduced into the air-tight space 39 a formed by the sheath 39,the tube member 36 a, the first connecting member 38, and the secondconnecting member 58 a through the hole 38 c of the first connectingmember 38. The introduced gas is blown out from the air-tight space 39 ato the outside of the insertion section 32 through the opening part 35a.

As shown in FIG. 15, in order to facilitate and ensure the fixation ofthe rigid endoscope 51 to the base end part 33 a of the dissector 31, aguiding groove 33 b is provided on the inner circumference surface of abase end part 33 a of the dissector 31 in the direction along the axisof the dissector 31. Further, to the guiding groove 33 b, a fixingmember 33 c is screwed. The fixing member 33 c is formed by bending aplate-shaped member made of metal into U-shape, further bending the bothends of the U-shape toward the inside of the U-shape so as to haveconvex-shaped parts. On the other hand, at a tip side of an eyepiece 53of the rigid endoscope 51, a convex part 52 a (see FIG. 10) is provided.

Further, a notched part 33 d is provided on the base end part 33 a and alight guide connector part 52 can move along the notched part 33 d.

When the operator inserts the rigid endoscope 51 from the base end partof the dissector 31, inserts the rigid endoscope 51 so that the convexpart 52 a enters along the guiding groove 33 b provided on the innercircumference surface of a base end part 33 a, and the light guideconnector part 52 enters along the notched part 33 d. When the rigidendoscope 51 is being inserted from the base end of the dissector 31,the convex part 52 a is moved along the inside of the guiding groove 33b, and moved ahead of the convex-shaped part of the fixing member 33 cmade of metal against the elastic force of the fixing member 33 c. Then,the light guiding connector part 52 is also moved along the notched part33 d provided on the base end part 33 a.

Accordingly, when the rigid endoscope 51 is inserted from the base endpart of the dissector 31, the positional relationship between thedissector 31 and the rigid endoscope 51 is set so that the light guideconnector part 52 enters the notched part 33 d and the convex part 52 aenters the guiding groove 33 b, and then, the rigid endoscope 51 isinserted into the dissector 31. When the rigid endoscope 51 is insertedinto the dissector 31, the convex part 52 a of the rigid endoscope 51 isengaged and fixed in a sandwiched manner by the fixing member 33 c inthe middle of the insertion, and the convex part of the rigid endoscope51 becomes not readily fallen off by the elastic force of the fixingmember 33 c.

Further, when the convex part 52 a is engaged and fixed, between therigid endoscope 51 and the dissector 31, sound implying that the rigidendoscope 51 is engaged arise, and the user can confirm by the soundthat the rigid endoscope 51 is set.

With reference to FIG. 16, an arranging relationship between the firstconnecting member 38 and the tube member 36 a which is made of metal andforms the rigid endoscope insertion channel 36 in the grip section 33will be described in detail. As shown in FIG. 16, the tip side of thetube member 36 a is fixed to the second connecting member 58 a and thebase end side of the tube member 36 a is fixed to a part of the base endside of the grip section 33. A central axis of the tube member 36 awhose both ends are fixed is, as shown in FIGS. 11 and 16, arranged onthe same axis AX as the central axis of the insertion section 32, andthe tube member 36 a is inserted through the central part of the firstconnecting member 38. As shown in FIG. 16, although the tube member 36 ais inserted through a hole 38 e in the central part of the firstconnecting part 38, a space 38 f is provided between the innercircumference surface of the hole 38 e and the outer circumferencesurface of the tube member 36 a. The space 38 f constitutes acommunication path which communicates with an inner space of the sheath39 and an inner space of the grip section 33.

That is, the tube member 36 a is loosely inserted through the hole 38 eof the first connecting member 38.

Since a space 38 f having an interval of d3 is provided between theinner circumference surface of the hole 38 e and the outer circumferencesurface of the tube member 36 a, the inner space of the sheath 39communicates with the inner space of the grip section 33 through thespace 38 f.

Further, on the outer member of the grip section 33, a space 33 e whichis a part from which the gas supplying tube 34 is inserted inside, andother spaces are provided. As the other spaces, for example, there is ahole (not shown) provided on the outer member of the grip section 33.Such holes constitute a communication path which communicates the innerspace with the outer space of the grip section 33.

Thus, the inner space of the sheath 39 communicates with the outer spaceof the grip section 33 through the space 38 f and the space 33 e.

According to the above structure, the carbon dioxide gas suppliedthrough the gas supplying tube 34 is introduced into the inner space ofthe sheath 39 through the hole 38 c of the first connecting member 38.The carbon dioxide gas is discharged from the hole 35 a into a bodycavity. By the introduction of the carbon dioxide into the body cavity,pressure in the body cavity increases. However, through the space 38 fand the space 33 e which communicate with the inner space of the sheath39 and the outer surface of the grip section 33, the carbon dioxide inthe body cavity is discharged.

Accordingly, in the case in which the carbon dioxide is supplied intothe body cavity by controlling the supplying amount of the carbondioxide supplied from the gas supplying tube 34 to be a predeterminedamount, if the pressure in the body cavity is increased, the carbondioxide in the sheath 39 is discharged to the outside space of the gripsection 33 through the space 38 f and the space 33 e. Thus, the space 38f and the space 33 e which form at least a part of the communicationpath, by releasing the carbon dioxide gas in the body cavity,constitutes pressure reducing means for reducing, that is, releasing thepressure in the body cavity so as to prevent the pressure from becomingbeyond a predetermined pressure. The predetermined pressure isdetermined by a relationship between a flow rate of the gas supply orthe like and a cross-sectional area of each space. A part having thesmallest cross-sectional area of the communication path is set to have asmaller cross-sectional area than a part having the smallestcross-sectional area of the gas supplying path. That is, the part havingthe smallest cross-sectional area of the gas supplying path is set tohave a larger cross-sectional area than the part having the smallestcross-sectional area of the communication path.

With reference to FIG. 17 through FIG. 24, a structure of the harvester41 will be described. As shown in FIG. 17, the harvester 41 mainlyincludes the insertion section 42 and a grip section 400 connected tothe insertion section 42. On a tip part of the insertion section 42 ofthe harvester 41 which is a cylindrical tube made of metal, the bipolarcutter 43 is provided at its upper part and the vein keeper 45, which isa holder, is provided at the inside of its lower part. If a bipolarcutter lever 401 and a vein keeper lever 402 provided on a grip section400 which is consecutively provided to the base end of the insertionsection 42, are moved forward and backward in the direction along thelongitudinal direction, in conjunction with the movements, the bipolarcutter 43 and the vein keeper 45 can be moved forward and backward aheadof the insertion section 42.

As to a structure of the base end side of the harvester 41, as shown inFIG. 18, the structure is similar to that of the base end side of thedissector 31 (see FIG. 15). Specifically, in the structure of the baseend side of the harvester 41, as shown in FIG. 18, a guiding groove 400b is provided on the inner circumference surface of a base end part 400Aof the harvester 41 in the direction along the axis of the harvester 41in order to facilitate and ensure the fixation of the rigid endoscope 51to the base end part of the harvester 41. Further, to the guiding groove400 b, a fixing member 400 c is screwed. The fixing member 400 c isformed by bending a plate-shaped member made of metal into U-shape,further bending the both ends of the U-shape toward the inside of theU-shape so as to have convex-shaped parts.

Further, a notched part 400 d is provided on the base end part 400A anda light guide connector part 52 can move along the notched part 400 d.

When the rigid endoscope 51 is inserted from the base end part of theharvester 41, the rigid endoscope 51 is inserted so that the convex part52 a of the rigid endoscope 51 is entered along the guiding groove 400 bprovided on the inner circumference surface of a base end part 400Ashown in FIG. 9, and the light guide connector part 52 is entered alongthe notched part 400 d. When the rigid endoscope 51 is being insertedfrom the base end of the harvester 41, the convex part of the rigidendoscope 51 is moved along the inside of the guiding groove 400 b, andmoved ahead of the convex-shaped part of the metal fixing member 400 cagainst the elastic force of the fixing member 400 c. Then, the lightguiding connector part 52 is also moved along the notched part 400 dprovided on the base end part 400A.

Accordingly, when the rigid endoscope 51 is inserted from the base endpart of the harvester 41, the positional relationship between theharvester 41 and the rigid endoscope 51 is set so that the light guideconnector part 52 enters the notched part 400 d and the convex part 52 aof the rigid endoscope 51 enters the guiding groove 400 b, and then, therigid endoscope 51 is inserted into the harvester 41. When the rigidendoscope 51 is inserted into the harvester 41, the convex part 52 a ofthe rigid endoscope 51 is engaged and fixed in a sandwiched manner bythe fixing member 400 c in the middle of the insertion, and the convexpart 52 a of the rigid endoscope 51 is not readily fallen off by theelastic force of the fixing member 400 c.

Further, when the convex part 52 a of the rigid endoscope 51 is engagedand fixed, between the rigid endoscope 51 and the harvester 41, soundimplying that the rigid endoscope 51 is engaged arise, and the user canconfirm by the sound that the rigid endoscope 51 is set.

As shown in FIG. 19, the vein keeper 45 of the harvester 41 is composedof a vein keeper axis 412 which holds a substantially U-shaped bloodvessel holding base 411 to be movable forward and backward in thelongitudinal axis direction, and a lock axis 414 which is movableforward and backward in the longitudinal axis direction against theblood vessel holding base 411 which forms a closed space 413 housing theblood vessel on the substantially U-shaped blood vessel holding base 411which is parallel to the vein keeper 412. The lock axis 414, in a stateshown in FIG. 19, forms the closed space 413 in a state locked to theblood vessel holding base 411 as well as the vein keeper axis 412.However, by releasing the locked state of the lock axis 414, as shown inFIG. 20, it is possible to release the closed space 413 and the lockaxis 414 can move forward and backward capable of housing the bloodvessel 11 in the closed space 413.

On the tip side surface of the insertion section 42 on which the bipolarcutter 43 is provided, a notch 415 is provided and a bipolar axis(described below) which moves the bipolar cutter 43 forward and backwardis inserted into the insertion section 42 through the notch 415. On theinner wall surface of the notch 415, a guard part 416 having anarch-shaped cross section is provided and on the inner surface of thetip of the insertion section 42, a wiper 417 for wiping an extraneousmatter adhered to a window part of the tip part of the rigid endoscope51 is provided. The wiper guard part is formed with an end of the wiper417 as an axis and the other end for sweeping the inside of the guardpart 416.

At one part of the cylindrically-shaped wiper guard part, a sweepinghole 419 a for sweeping the extraneous matter 418 (see FIG. 21) wiped bythe wiper 417 is provided. As the extraneous matter 418, blood, fat,smoke due to the electric knife or the like can be considered. The wiper417 sweeps by operating a wiper lever 419 (see FIG. 17) through a wiperaxis (not shown, see FIG. 25). As shown in FIG. 21 which is anillustration viewed from the direction of the arrow A of FIG. 19, at aposition inside from the tip surface of the insertion section 42 by apredetermined distance, an opening of a rigid endoscope insertionchannel 420 in which the rigid endoscope 51 is inserted and an openingof a gas supplying channel 421 are adjacently provided.

As shown in FIG. 22, along the axis direction of the harvester 41, ametal tube member 420 a which forms the rigid endoscope insertionchannel 420 is inserted inside the harvester 41 from the base end sideof the grip section 400 to the tip part of the insertion section 42. Inthe middle, inside of the insertion section 42 of the metal tube, aplurality of holding members 42 a is arranged. The bipolar cutter 43 isconnected to the bipolar cutter lever 401 provided on the grip section400 by a bipolar axis 450 which is inserted through the insertionsection 42. If the bipolar cutter lever 401 is moved forward andbackward along the longitudinal axis, the force of the movement istransmitted to the bipolar cutter 43 through the bipolar axis 450, andit is possible to move the bipolar cutter 43 forward and backward aheadof the insertion section 42.

Similarly, the vein keeper 45 is connected to the vein keeper lever 402provided on the grip section 400 by a vein keeper axis 412 which isinserted through the insertion section 42. If the vein keeper lever 402is moved forward and backward along the longitudinal axis, the force ofthe movement is transmitted to the vein keeper 45 through the veinkeeper axis 412, and it is possible to move the vein keeper 45 forwardand backward ahead of the insertion section 42.

A metal tube 420 b which forms the rigid endoscope insertion channel 420is fixed in the insertion section 42 by a plurality of holding members42 a (see FIG. 25). The two bipolar axes 450, the vein keeper axis 412,the lock axis 414, and the wiper axis are not fixed in the insertionsection 42 (see FIG. 25). The two bipolar axes 450, the vein keeper axis412, and the lock axis 414 are configured to be movable forward andbackward in the longitudinal axis direction of the insertion section 42,and the wiper axis is configured to be rotatable about the wiper axis.

The vein keeper lever 402 and the vein keeper axis 412 are integrallymovable in the inner surface of the grip section 400 by a click assembly451 which pin pressing the inner surface of the grip section 400. If theclick assembly 451 positions, for example, one of three click grooves452 provided on the inner surface of the grip section 400, the veinkeeper lever 402 and the vein keeper axis 412 can be stably held at theposition. If the operator adds force to the longitudinal axis, the clickassembly 451 can be readily thrown out from the click groove 452.

The vein keeper lever 402 is removably connected with the lock lever453, and by depressing a lock button 454, the vein keeper lever 402 canbe separated from the lock lever 453. The lock lever 453 is connectedwith the lock axis 414, and by moving the lock lever 453 forward andbackward in a state being separated from the vein keeper lever 402, thelock lever 453 can be moved forward and backward being capable ofhousing the blood vessel 11 within the closed space 413 (see FIGS. 19and 20).

As shown in FIG. 23, the vein keeper lever 402 is strongly fixed to thevein keeper axis 412 by screw 460 and gluing.

As shown in FIGS. 24 and 25, along the axis direction of the harvester41, a gas supplying pipe 461 made of metal and forms a gas supplychannel is inserted in the harvester 41 from the base end side of thegrip section 400 to the tip part of the insertion section 42. At one endof the gas supplying pipe 461 of the grip section 400, a gas supplyingtube 44 is fitted in the grip section 400, a gas supplying connector 44a is provided at a base end of the gas supplying tube 44, and the gassupplying connector 44 a is connected to a connector of a tube connectedto the gas supplying device 108.

As described above, in the embodiment, as shown in FIG. 26, by movingthe vein keeper lever 402 forward and backward, it is possible to movethe vein keeper 45 forward and backward at the tip. Accordingly, forexample, as shown in an endoscopic image in FIG. 27, if a state of thebranch 11A is hard to see when cutting the branch 11A, by moving thevein keeper lever 402 forward in the longitudinal axis direction asshown in FIG. 28, the tip of the vein keeper 45 moves forward, and it ispossible to see an endoscopic image suitable for confirming the state ofthe branch 11A.

With reference to FIGS. 29 and 30, the bipolar cutter 43 which isinserted in the harvester 41 now will be described.

As shown in FIG. 29, the bipolar cutter 43 has a cutter body 422 whichis a branch holding member made of a transparent insulating member, avoltage application electrode 425 which is one of electrodes in thebipolar, and a feedback electrode 424 which is another electrode of theelectrodes in the bipolar. As shown in FIG. 30, the bipolar cutter 43has a three-layered structure formed by an upper layer of the feedbackelectrode 424, the cutter body 422, and the voltage applicationelectrode 425.

The cutter body 422 has a v-shaped groove 436 formed at the tip side,and at the base end side of the v-shaped groove 436, a slit groove 427having, for example, a width of 0.5 mm, is formed.

When the branch 11A is cut, the branch 11A is guided to the slit groove427 along the v-shaped groove 436 of the cutter body 422, by the branch11A pushed and entered in the slit groove 427, the branch 11A is held inthe slit groove 427 in a compressed state. In the state, by applying ahigh-frequency current from the voltage application electrode 425 to thefeedback electrode 424, the branch 11A is cut and stanched.

Since a contact area of the feedback electrode 424 is larger than thatof the voltage application electrode 425, the current efficientlyconcentrates to the voltage application electrode 425, and it ispossible to perform the incision part and blood stanching.

Thus constructed bipolar cutter 43 can be manufactured inexpensivelywhile having excellent workability and heat-durability and the bloodstanching performance of the living body tissue such as a blood vessel(branch 11A) to be cut can be increased by configuring the bipolarcutter 43 as described below. That is, if in the bipolar cutter 43, thecutter body 422 is entirely made of synthetic resin, the durability maybe slightly lost due to heat generated by a discharge between the twoelectrodes 424 and 425. On the other hand, if the cutter body 422 ismade of ceramics having heat-durability, the manufacturing cost ishigher and the workability is inferior to the above case.

Moreover, as described above, the bipolar cutter 43 cuts the living bodytissue (branch 11A) by a thermal action of the discharge ofhigh-frequency current from the one voltage application electrode 425 tothe other feedback electrode 424. Accordingly, it can be possible toreduce the possibility of damage due to heat without entirely formingthe bipolar cutter by using ceramics, but by forming only between thepair of electrodes, particularly, the part of the bipolar cutter whichcontacts with the voltage application side electrode by using ceramicshaving heat-durability. That is, in the bipolar cutter, it is preferableto form most of the cutter body by using synthetic resin which isinexpensive and excellent in workability, and provide a ceramics memberbetween the pair of electrodes.

However, ceramics has higher thermal conductivity than synthetic resinsuch as polycarbonate. Accordingly, in the bipolar cutter, heatgenerated at the voltage application electrode and the living bodytissue to be cut due to the high-frequency current discharged betweenthe pair of electrodes extensively transmits to the member made ofceramics. As a result, the amount of heat consumption at the living bodytissue to be cut is reduced at the time of cutting, and the bloodstanching performance is reduced.

Accordingly, in consideration of the above problems, the bipolar cutter43 can be configured as described below.

As shown in FIG. 31 through FIG. 35, the bipolar cutter 43 includes acutter body 422, a tissue holding part 423, a voltage applicationelectrode 425 which is a first electrode to be one of electrodes in thebipolar, and a feedback electrode 424 which is a second electrode to beanother electrode of the electrodes in the bipolar, two lead wires 428(a voltage application side lead wire 428 a, a feedback side lead wire428 b), and a lead wire cover 426.

The cutter body 422 is made of, as described above, for example, asynthetic resin which is a transparent insulating member such aspolycarbonate. The cutter body 422 has, when viewed from the axis in thelongitudinal direction, a cross section curved in arch-shape (see FIG.35) so as to fit the arch-shaped inner circumference surface of a notchpart 415 (see FIGS. 21 and 22) in the harvester 41.

The cutter body 422 includes a v-shaped groove 436 formed at the tip, afitting part 435 in which the tissue holding part 423 is fitted(described below), a groove part 422 j in which the lead wire 428 a ofthe voltage application side and the lead wire 428 b of the feedbackelectrode side are arranged respectively in an insulated state, and thelead wire cover 426 a is fitted, and a concave part 4221 on which thefeedback electrode 424 is arranged. At the bottom surface of the groovepart 422 j, two long grooves are formed through the entire length of thegroove part 422 j to retain the insulated state between the lead wire428 a of the voltage application side and the lead wire 428 b of thefeedback side.

The fitting part 435 is composed of a first groove part 435 a formed inslit-shape from the v-shaped groove 436 at the tip of the cutter body422, and a second groove part 435 b formed in substantially circularshape at the base end side when viewed from upward direction.

Further, to the cutter body 422, a step part 422 a (see FIGS. 32 and 35)to be an inward flange at the inner circumference surface where afitting part 435 is to be formed and on the position corresponding tothe base end of the tissue holding part 423, a concave groove part 422 bfor fitting (see FIGS. 31 and 34) is formed.

To the groove in which the lead wire of the voltage application side ofthe groove part 422 j is arranged, a penetration part 422 e (see FIGS.32 and 33) in which a lead wire connecting part 425 a of the voltageapplication electrode 425 is inserted at the tip side, is provided.Accordingly, at the voltage application electrode 425 arranged at theunder surface side of the cutter body 422, the lead wire connecting part425 a is inserted into the penetration part 422 e, and the end part ofthe lead wire connecting part 425 a and the lead wire 428 a of thevoltage application side arranged on the upper surface of the groovepart 422 j come to be electrically connectable.

Further, the cutter body 422 has three fastening parts 422 c on theupper surface and under surface, two of the fastening parts 422 cupwardly protrude at the tip side of the concave part 4221, and the onefastening part 422 c downwardly protrudes. These fastening parts 422 care inserted into hole parts 425 b and 424 a pierced in the voltageapplication electrode 425 and the feedback electrode 424. After thefastening parts 422 c are melted, for example, by thermal caulking, andthe fastening parts 422 c coagulate in outer flange shape (see FIGS. 34and 35), the feedback electrode 424 and the voltage applicationelectrode 425 are respectively fixed on the upper and under surfaces ofthe cutter body 422.

The feedback electrode 424 is a metal plate which has a curved crosssection when viewed along the upper surface of the concave part 4221 ofthe cutter body 422 from the longitudinal axis direction. The feedbackelectrode 424 has a notched part notched in keyhole-shape and theabove-described two hole parts 424 a when viewed from a boundary of thecutter body 422 and the upper surface of the tissue holding part 423,that is, substantially along each boundary. Moreover, the feedbackelectrode 424 has a lead wire connecting part 424 b electricallyconnected with a feedback side lead wire at the base end part by weldingand a protruding part 424 c juxtaposed with the lead wire connectingpart 424 b and fitted and held in the groove part 422 j of the cutterbody 422.

Further, the lead wire connecting part 424 b and the protruding part 424c are bent down below substantially at a right angle respectively,further, bent substantially at a right angle so as to extend toward thebase end side. The lead wire connecting part 424 b is longer in theextending length toward the base end side than the extending length ofthe protruding part 424 c, and has an enough length for the weldingconnection with the feedback side lead wire.

The protruding part 424 c is shorter in the extending length toward thebase end side than the length from the base end of the concave part 4221of the cutter body 422 to the penetration part 422 e of the groove part422 j. Thus, the insulation is retained without the protruding part 424c contacting with the lead wire connecting part 425 a of the voltageapplication electrode 425 and the voltage application side lead wire 428a, and the insulation between the feedback electrode 424 and the voltageapplication electrode 425 is also held.

The voltage application electrode 425 is a substantiallyrectangular-shaped metal plate arranged on the under surface side of thecutter body 422 and the tissue holding part 423, and has theabove-described hole part 425 b. From the voltage application electrode425, as described above, the lead wire connecting part 425 a, which iselectrically connected with the voltage application side lead wire 428 aby welding, extends toward the base end side. In the lead wireconnecting part 425 a, the end part in the extending direction isupwardly bent at substantially right angle and further, the end part isbent at substantially right angle in the extending direction.

The voltage application side lead wire 428 a and the feedback side leadwire 428 b are respectively arranged in parallel in two long groovesformed on the bottom surface of the groove part 422 j of the cutter body422 so as to be insulated, and electrically connected with the externalelectric knife device 107 (see FIG. 2).

The tissue holding part 423 is arranged at substantially center of thetip part of the cutter body 422, and made of ceramics which is aheat-resistant member. That is, if the cutter body 422 is entirely madeof ceramics, the manufacturing cost is higher than that of syntheticresin, and inferior in workability. Therefore, in the bipolar cutter 43according to the embodiment, only the tissue holding part 423 is made ofceramics having heat-resistance to reduce the manufacturing cost and hasexcellent workability.

The tissue holding part 423 is formed in so-called keyhole-shape asshown in FIG. 38 through FIG. 40, and has a cylindrically-shaped part423A formed in substantially cylindrical shape at the base end part, anda rectangular-shaped part 423B extending from the peripheral sidesurface of the cylindrically-shaped part 423A and in which a slit groove427 is formed. The tissue holding part 423 shown in FIG. 26 illustratesthe surface to be under surface side when inserted in the cutter body422.

As shown in FIG. 35, the tissue holding part 423 extends along thelongitudinal axis direction, and has two arm parts 423 a each outwardlyprotruding from both side surfaces of the rectangular-shaped part 423B,and convex part 423 b protruding from the side circumference surface ofthe base end part of the cylindrically-shaped part 423A toward the baseend side.

The tissue holding part 423 is fitted into the fitting part 435 of thecutter body 422, the two arm parts 423 a are held in the step part 422 aof the first groove part 435 a, and the convex part 423 b is fitted andheld in the concave part for fitting 422 b of the cutter body 422. Thus,the tissue holding part 423 is fitted to the cutter body 422.

Further, in the tissue holding part 423, a substantiallycircumferentially-shaped groove part 440 is formed in thecylindrically-shaped part 423A. As shown in FIG. 33, the groove part 440is separated by a predetermined distance from the substantially tip partof the voltage application electrode 425 which covers the base end partof the slit groove 427, surrounds the tip part of the voltageapplication electrode 425 as if drawing a circle, and a bottomed grooveformed, for example, in a width of about 0.5 mm and a depth of 1 to 2mm. It is not limited that the groove 440 is formed in the substantiallycircumferential shape, any shape, for example, polygonal shape such asrectangular, or triangle can be possible as long as the groove part 440is separated by the predetermined distance from the substantially tippart of the voltage application electrode 425 which covers the base endpart of the slit groove 427. Moreover, the width and depth of the groovepart 440 are set so that the tissue holding part 423 can maintain apredetermined strength.

The slit groove 427 is provided by being grooved in the longitudinaldirection of the tissue holding part 423 from the tip central part ofthe substantially rectangular-shaped part 423B to the substantiallycentral part of the substantially cylindrical part 423A, for example, ina width of 0.5 mm.

The tissue holding part 423 is made of a high-heat-resistant ceramicsstructural material, for example, zirconia or alumina.

On the under surface of the tissue holding part 423, a step part 430which is notched toward the base end side so as to position the tip partof the voltage application electrode 425 is formed.

In the harvester 41, if ceramics which has higher thermal conductivitythan synthetic resins such as polycarbonate is used for the bipolarcutter 43, the heat generated at the voltage application electrode 425and the branch 11A serving as the living body tissue to be cut due tothe high-frequency current discharged between the electrodes 424 and 425extensively transmits to the tissue holding part 423 made of ceramics.As a result, the amount of heat consumption at the branch 11A is reducedat the time of cutting, and the blood stanching performance is reduced.However, the bipolar cutter 43 according to the embodiment can solve theabove problems by the groove part 440 of the tissue holding part 425formed of ceramics between the electrodes 424 and 425.

A cutting operation of the branch 11A by using thus configured bipolarcutter 43 of the harvester 41 will be described in detail with referenceto the flowchart in FIG. 4 and FIG. 39 through FIG. 41. As describedabove according to the flowchart of FIG. 4, after the peripheral tissuesof the entire length of the blood vessel 11 are dissected by using thedissector 31 (S4), then, the dissector 31 is pulled out from the trocar21, while the trocar 21 is being left, the harvester 41 is inserted, anda cutting operation of the branches 11A of the blood vessel 11 from theincision part 16 to the ankle 14 is performed (S5).

During the operation, the operator operates the bipolar cutter lever 401of the harvester 41 in the direction the bipolar cutter 43 moves forwardso that the branch 11A enters the v-shaped groove 436 of the cutter body422 while confirming the endoscopic image. By the operation, the branch11A is guided into the slit groove 427 of the tissue holding part 423 bythe v-shaped groove 436.

The operator confirms that the branch 11A is entered into the slitgroove 427 and as shown in FIG. 39, the branch 11A is in contact withthe voltage application electrode 425 by the endoscopic image, andapplies a high-frequency current from the electric knife device 107.Then, the high-frequency current discharged form the voltage applicationelectrode 425 discharges to the feedback electrode 424 through thebranch 11A.

At the part the branch 11A in the slit groove 427 of the tissue holdingpart 423 and the voltage application electrode 425 in contact with eachother, heat is generated due to the discharge from the voltageapplication electrode 425 and as shown in FIG. 40, the branch 11Acoagulates and is cut.

With reference to FIG. 41, a flow of the conduction of the heatgenerated at the branch 11A to which the high-frequency current form thevoltage application electrode 425 is applied, and conducted to thetissue holding part 423 will be described.

In the description below, a side surface of the groove part 440 of theinner circumference side of the tissue holding part 423 is a wallsurface 440 a, a side surface of the outer circumference side is 440 b,and the part where the voltage application electrode 425 and the branch11A come in contact with each other is a heat generating part 480.

As described above, the amount of heat generated at the branch 11A isradially conducted to the tissue holding part 423 and conducted to thegroove part 440. The amount of heat conducted to the groove 440 dependson thermal conductivity λ of the tissue holding part 423 and the groovepart 440.

Heat flow flux qa of the tissue holding part 423 from the heatgenerating part 480 to the wall surface 440 a can be calculatedaccording to the formula (1).qa=λa(th−twh)/δ1  formula(1)qa: heat flow fluxλa: thermal conductivity of the tissue holding part 423th: temperature at the interface between the tissue holding part 423(slit groove 427) and the branch 11Atwh: temperature at the interface between the wall surface 440 a and airδ1: distance from the slit groove 427 in contact with the branch 11A tothe wall surface 440 a

On the other hand, a heat flow flux qb of the groove 440 between thewall surfaces 440 a and 440 b of the tissue holding part 423 can becalculated according to the formula (2).qb=λair(twh−tc)/δ2  formula(2)λair: thermal conductivity of airtc: temperature at the interface between the wall surface 440 b and airδ1: distance from the wall surface 440 a to the wall surface 440 b

As will be understood from the formulas (1) and (2), the value of theheat flow flux q depends on the value of the thermal conductivity λwhich is a product value. That is, as compared to the thermalconductivity λa of the tissue holding part 423 made of ceramics, thethermal conductivity λair of air is extremely small. Accordingly, theheat flow flux qb at the groove part 440 depends on the value of thethermal conductivity λair of air which is a product value, as comparedto the heat flow flux qa of the tissue holding part 423, the heat flowflux qb at the groove part 440 becomes extremely small.

As a result of the above, in the tissue holding part 423, the amount ofheat consumption increases at a part from the heat generating part 480(a part of the slit groove 427) which holds the branch 11A to which heatis supplied from the voltage application electrode 425 to the groovepart 440. That is, in the tissue holding part 423, rapid heat conductionis reduced by the groove part 440, and only the part from the heatgenerating part 480 to the groove 440 comes to have a high temperature.Accordingly, the blood stanching performance of the branch 11A increasesdue to the increased heat consumption of the branch 11A.

Therefore, in the bipolar cutter 43 according to this embodiment, it ispossible to prevent the durability decreasing due to the heat generatedby discharge by forming only the part between the pair of electrodes 424and 425, especially, the part which is in contact with the voltageapplication electrode 425 by using ceramics without forming the entireof the bipolar cutter 43 using ceramics.

That is, in the tissue holding part 423, the heat conduction from thegroove part 440 to the part of the outer circumference side becomesdifficult because the groove part 440 is provided. As a result, at thepart from the groove part 440 to the part of the outer circumferenceside in the tissue holding part 423, the rapid temperature increase canbe reduced. Accordingly, the temperature increase in the cutter body 422in which the tissue holding part 423 is inserted can be also reduced.Therefore, even if the cutter body 422 is made of synthetic resin whoseworking temperature is low, heat durability can be ensured.

The groove part 440 is formed by being notched from the surface (in theembodiment, under surface) of the tissue holding part 423 on which thevoltage application electrode 425 is arranged. Accordingly, the amountof heat concentrating around the voltage application electrode 425 whichcomes in contact with the branch 11A and conducting to the tissueholding part 423 is reduced due to the groove part 440. Therefore, thetemperature in the vicinity of the voltage application electrode 425becomes the highest due to the amount of heat the tissue holding part423 consumes, as described above, and the amount of heat necessary forthe blood stanching of the branch 11A is ensured.

As a result, the bipolar cutter 43 of the harvester 41, which is thecutting means in the embodiment, is excellent in heat durability and cancut the branch 11A of the harvesting target blood vessel 11, which is aliving body tissue, while the blood stanching is ensured.

As described above, in order to retain a creepage distance forinsulation for withstanding voltage, the central part of the feedbackelectrode 424 is notched in substantially round shape substantiallyaround the base end part of the slit groove 427 so that a distance fromthe tip part of the voltage application electrode 425 positioned at thebase end side of the slit groove 427, that is, the heat generating part480, to the feedback electrode 424 becomes substantially equal.

Accordingly, the heat generated in the voltage application electrode 425is conveyed substantially uniformly to the tissue holding part 423 byproviding the surface of the tissue holding part 423 on the side of thefeedback electrode 424 in substantially round shape to correspond tothat of the feedback electrode 424, that is to say, to match the surfaceshape of the cylindrically-shaped part 423A of the tissue holding part423.

As a result, on the upper surface side of the tissue holding part 423 tobe a contact surface between the cutter body 422 and the feedbackelectrode 424, and the voltage application electrode 425, it is possibleto reduce partial high temperature. That is, on the upper surface of thetissue holding part 423, since the heat generated in the heat generatingpart 480 is equally conducted, it is possible to prevent the cutter body422 and the tissue holding part 423 from having a high temperature.

In this embodiment, the tissue holding part 423 made of ceramics inwhich the groove part 440 is formed at the tip central part of thecutter body 422 is provided. However, all tip parts of the cutter body422 between the feedback electrode 424 and the voltage applicationelectrode 425 can be formed with ceramics member having the groove part440.

Further, λair, the thermal conductivity of air, is affected by theatmosphere temperature. However, since the amount of heat consumptionagainst the branch 11A increases, the discharging time of thehigh-frequency current from the voltage application electrode 425 to thefeedback electrode 424 can be reduced.

As shown in FIGS. 42 and 43, in this embodiment, the dissector 31 isintegrally formed with the gas supplying tube 34 and the gas supplyingconnector 34 a. Further, the harvester 41 is integrally formed with theelectrical cable 47, the connector 470 provided at the base end of theelectrical cable 47, the gas supplying tube 44 and the gas supplyingconnector 44 a. Thus, in the surgery system 101 according to thisembodiment, the dissector 31 and the harvester 41 can be structured tobe disposable.

As to the harvester 41, the harvester 41 is configured to release thecarbon dioxide gas outside so that the pressure in the body cavity doesnot exceed a predetermined value when the carbon dioxide gas suppliedfrom the gas supplying tube 44 is supplied into the body cavity from thegas supplying channel 421. More particularly, as shown in FIG. 25, theplurality of holding members 42 a are arranged inside of the insertionsection 42 which is a tube member. As described above, in the insertionsection 42, the metal tube 420 b is fixed to the holding members 42 abut the other contents, the two bipolar axes 450, the vein keeper axis412, the lock axis 414, and the wiper axis are not fixed. That is, thetwo bipolar axes 450, the vein keeper axis 412, the lock axis 414, andthe wiper axis are loosely inserted into the plurality of holes providedin the holding members 42 a. Accordingly, in each hole, the space 42 bis formed between the contents.

The supplied carbon dioxide gas is supplied into the body cavity fromthe gas supplying channel 421, and the body cavity is communicated withthe inner space of the grip section 400 through the above-describedspace 42 b in the insertion section 42. That is, the space 42 bconstitutes a communication path for communicating the outer space ofthe insertion section 42 with the inner space of the grip section 400.

Further, on the outer member of the grip section 400, a space 400 a as apart for inserting the gas supplying tube inside, and other spaces areprovided. The other spaces are, for example, holes provided on the outermember of the grip section 400 (not shown). These spaces constitute acommunication path for communicating the inner space with the outerspace of the grip section 400.

Accordingly, the inner space of the insertion section 42 is communicatedwith the outer space of the grip section 400 through the space 42 b andthe space 400 a.

According to the above structure, the carbon dioxide gas suppliedthrough the gas supplying tube 44 is introduced into the body cavityfrom the tip part of the insertion section 42 through the gas supplyingchannel 421. By the introduction of the carbon dioxide gas into the bodycavity, pressure in the body cavity increases. However, from the tippart of the insertion section 42, the carbon dioxide gas in the bodycavity is discharged through the above-described space 42 b and thespace 400 a.

Thus, while controlling the supplying amount of the carbon dioxidesupplied from the gas supplying tube 44 to be a predetermined amount, ifthe carbon dioxide is supplied into the body cavity and the pressure inthe body cavity is beyond a predetermined pressure, the carbon dioxidegas is discharged to the outer space of the grip section 400 from thetip part of the insertion section 42 through the space 42 b and thespace 400 a. Accordingly, the space 42 b and the space 400 a which format least a part of the communication path, by releasing the carbondioxide gas in the body cavity, constitutes pressure reducing means forreducing, that is, releasing the pressure in the body cavity so as toprevent the pressure from becoming beyond the predetermined pressure.The predetermined pressure is determined by a relationship between aflow rate of the gas supply or the like and a cross-sectional area ofeach space. A part having the smallest cross-sectional area of thecommunication path is set to have a smaller cross-sectional area than apart having the smallest cross-sectional area of the gas supplying path.That is, the part having the smallest cross-sectional area of the gassupplying path is set to have a larger cross-sectional area than thepart having the smallest cross-sectional area of the communication path.

As described above, by using the dissector 31 and the harvester 41according to this embodiment, even when harvesting the subcutaneousvessel such as great saphenous vein under endoscopic observation, it ispossible to control the gas pressure in the body cavity so that thepressure does not increase beyond the predetermined pressure.

Second Embodiment

A second embodiment of the present invention will be described. In theabove-described structure according to the first embodiment, through thespace 38 f and the space 33 e which communicate with the inner space ofthe sheath 39 and the outer space of the grip section 33 of thedissector 31, the carbon dioxide in the body cavity is discharged. In aliving body tissue harvesting apparatus according to the secondembodiment, as shown in FIG. 44 through FIG. 46, a channel for dischargeis provided to the insertion section of the dissector 31 to positivelydischarge the carbon dioxide gas.

FIG. 44 through FIG. 46 illustrate the structure according to the secondembodiment of the present invention. FIG. 44 is a partial crosssectional view of the tip part of the insertion section 32 along theinsertion axis. FIG. 45 is a partial cross sectional view of the tippart of the grip section 33 along the insertion axis. FIG. 46illustrates positions of opening parts of each hole in the insertionsection 32. In the FIG. 44 through FIG. 46, the same numbers are givento the constituents corresponding to the constituents described in thefirst embodiment, and detailed description is omitted in thisembodiment.

As shown in FIG. 44, to the second connecting member 58 a, more than onehole 35 c which has an opening part 35 b on the outer circumferencesurface is provided. In this embodiment, three holes 35 c are provided.In particular, each hole 35 c is formed in the direction from the outercircumference toward the inner circumference of the second connectingmember 58 a, and in the middle of the second connecting member 58 a,toward the base end side of the insertion section 32. Accordingly, thehole 35 c has a substantially L-shape. To the base end side of thesecond connecting member 58 a, a discharge tube 34 b which constitutes adischarge channel communicating with the inner space of the hole 35 c isconnected.

On the other hand, as shown in FIG. 45, the base end side of thedischarge tube 34 b is connected to the tip surface of the firstconnecting member 38. To the first connecting member 38, a hole 38 g isformed from the tip surface toward the base end surface. One end of thedischarge tube 34 b is connected to an opening part of the hole 38 g ofthe tip side of the first connecting member 38. The hole 35 c, thedischarge tube 34 b, and the hole 38 g constitute a communication pathcommunicating the outer space of the insertion section 32 with the innerspace of the grip section 33.

FIG. 46 is a partial perspective view illustrating the positions of theopenings 35 a and 38 g formed on the tip part of the insertion section32. The three opening parts 35 a are provided on the sheath 39 atintervals of angle of 120 degrees around the central axis of theinsertion section 32 along the periphery direction. Similarly, threeopening parts 35 b are provided on the second connecting member 58 a atintervals of angle of 120 degrees around the central axis of theinsertion section 32 along the periphery direction.

These three opening parts 35 b are separated from each opening part 35 aby a predetermined distance in the axis direction of the insertionsection 32, and arranged at a position rotated by a predetermined angle,for example, 60 degrees, around the central axis of the insertionsection 32 so that each opening part 35 b and opening parts 35 a do notoverlap each other when viewed from the axis direction of the insertionsection 32.

According to the above structure, the carbon dioxide supplied from onegas supplying tube 34 is supplied into the body cavity from the threeopening parts 35 a, from the three opening parts 35 b through the threedischarge tubes 34 b and spaces 33 e, discharged to the outer space ofthe grip section 33. Accordingly, the communication path at least a partof which is formed by the hole 35 c, the discharge tube 34 b, and thehole 38 g, by releasing the carbon dioxide gas, constitutes pressurereducing means for reducing, that is, releasing the pressure in the bodycavity so as to prevent the pressure from becoming beyond apredetermined pressure. The predetermined pressure is determined by arelationship between a flow rate of the gas supply or the like andcross-sectional areas of the inner channels of these three dischargetubes 34 b. A part having the smallest cross-sectional area of thecommunication path is set to have a smaller cross-sectional area than apart having the smallest cross-sectional area of the gas supplying path.That is, the part having the smallest cross-sectional area of the gassupplying path is set to have a larger cross-sectional area than thepart having the smallest cross-sectional area of the communication path.

In the above description, in the structure of the dissector 31, the casein which the channels for discharging the carbon dioxide are positivelyprovided in the insertion section is described. Similarly, in theharvester 41, a channel for discharging carbon dioxide can be positivelyprovided in the insertion section.

Third Embodiment

A third embodiment of the present invention will now be described. Inthe structures according to the above-described the first and secondembodiments, carbon dioxide in the body cavity is discharged through thespace 38 f and the space 33 e which are communicating with the innerspace of the sheath 39 and the outer of the grip section 33 of thedissector 31, or the channels provided on the insertion section. Aliving body tissue harvesting apparatus according to the thirdembodiment, as shown in FIG. 47, has a relief valve 200 in the middle ofthe gas supplying tube 34.

FIG. 47 is an illustration for explaining the structure according to thethird embodiment of the present invention. FIG. 47 is a partialcross-sectional view of the dissector 31 according to the thirdembodiment of the present invention. In FIG. 47, the same numbers aregiven to the constituents corresponding to the constituents described inthe first embodiment, and detailed description is omitted in thisembodiment.

As shown in FIG. 47, since the relief valve 200 is provided in themiddle of the gas supplying tube 34, if pressure in the relief valve 200exceeds a pressure set at the relief valve 200, carbon dioxide gas inthe gas supplying tube 34 is discharged. Therefore, the pressure in thebody cavity does not become beyond the predetermined pressure. Becausethe relief valve 200 releases the carbon dioxide gas, pressure reducingmeans for reducing, that is, releasing the pressure in the body cavityso as to prevent the pressure from becoming beyond the predeterminedpressure, is composed. The relief valve 200 can be provided on the baseend side of the sheath 39 of the insertion pert 32. By providing therelief valve 200 on the base end side of the sheath 39, if the pressurein the airtight space 39 a becomes beyond the predetermined pressure,the carbon dioxide gas in the airtight space 39 a is discharged.

In the above description, in the structure of the dissector 31, the casein which the relief valve 200 is provided to the gas supplying tube 34or the sheath 39 of the insertion section 32 is described. Similarly, inthe harvester 41, the relief valve 200 can be provided in the gassupplying tube 44 or the insertion section 42.

While the present invention has been described with reference to theembodiments, it is to be understood that the invention is not limited tothe disclosed embodiments. And various changes and modifications thereofcould be made without departing from the spirit and scope of theinvention as defined in the appended claims. Further, each of the aboveembodiments includes the invention at various steps, and by combining aplurality of features, various combination of the invention can beextracted.

For example, even if some features are deleted from the whole featuresshown in each embodiment, if the problem described in the section ofBACKGROUND OF THE INVENTION can be solved, and the advantages describedin the section of SUMMARY OF THE INVENTION can be obtained, thestructure in which some features are deleted can be extracted as theinvention.

1. A living body tissue harvesting apparatus having a grip section and atubular insertion section connected to the grip section and to beinserted into a body cavity, the living body tissue harvesting apparatuscomprising: a gas supplying path for supplying a predetermined gas froman external gas supplying device into the insertion section; a firstopening part provided on the insertion section, the first opening partdischarging, through the insertion section, the predetermined gassupplied through the gas supplying path; and a communication pathprovided in the insertion section for communicating with outside throughthe grip section.
 2. The living body tissue harvesting apparatusaccording to claim 1, wherein a part having the smallest cross-sectionalarea in the gas supplying path is larger in terms of cross-sectionalarea than a part having the smallest cross-sectional area in thecommunication path.
 3. The living body tissue harvesting apparatusaccording to claim 1, wherein the insertion section has a mounting partfor mounting an endoscope.
 4. The living body tissue harvestingapparatus according to claim 2, wherein the insertion section has amounting part for mounting an endoscope.
 5. The living body tissueharvesting apparatus according to claim 3, wherein the mounting part isinserted into the insertion section and functions as a channel intowhich the endoscope is inserted.
 6. The living body tissue harvestingapparatus according to claim 4, wherein the mounting part is insertedinto the insertion section and functions as a channel into which theendoscope is inserted.
 7. The living body tissue harvesting apparatusaccording to claim 1, wherein at least a part of the communication pathis formed by a space communicating the inner space of the insertionsection with the inner space of the grip section.
 8. The living bodytissue harvesting apparatus according to claim 2, wherein at least apart of the communication path is formed by a space communicating theinner space of the insertion section with the inner space of the gripsection.
 9. The living body tissue harvesting apparatus according toclaim 3, wherein at least a part of the communication path is formed bya space communicating the inner space of the insertion section with theinner space of the grip section.
 10. The living body tissue harvestingapparatus according to claim 5, wherein at least a part of thecommunication path is formed by a space communicating the inner space ofthe insertion section with the inner space of the grip section.
 11. Theliving body tissue harvesting apparatus according to claim 7, whereinthe communication path is a hole provided in a connecting memberconnecting the insertion section and the grip section, and at least apart is formed by a space formed by the hole and an outer circumferencesurface of the tubular member which forms the channel.
 12. The livingbody tissue harvesting apparatus according to claim 1, wherein thecommunication path communicates the outer space of the insertion sectionwith the inner space of the grip section.
 13. The living body tissueharvesting apparatus according to claim 2, wherein the communicationpath communicates the outer space of the insertion section with theinner space of the grip section.
 14. The living body tissue harvestingapparatus according to claim 3, wherein the communication pathcommunicates the outer space of the insertion section with the innerspace of the grip section.
 15. The living body tissue harvestingapparatus according to claim 5, wherein the communication pathcommunicates the outer space of the insertion section with the innerspace of the grip section.
 16. The living body tissue harvestingapparatus according to claim 1, further comprising: a tube inserted intoand provided in the insertion section and connected to the communicationpath; and a second opening that is provided in the insertion section andthat communicates the body cavity with the outside as an opening of thetube.
 17. The living body tissue harvesting apparatus according to claim2, further comprising: a tube inserted into and provided in theinsertion section and connected to the communication path; and a secondopening that is provided in the insertion section and that communicatesthe body cavity with the outside as an opening of the tube.
 18. Theliving body tissue harvesting apparatus according to claim 3, furthercomprising: a tube inserted into and provided in the insertion sectionand connected to the communication path; and a second opening that isprovided in the insertion section and that communicates the body cavitywith the outside as an opening of the tube.
 19. The living body tissueharvesting apparatus according to claim 5, further comprising: a tubeinserted into and provided in the insertion section and connected to thecommunication path; and a second opening that is provided in theinsertion section and that communicates the body cavity with the outsideas an opening of the tube.
 20. A living body tissue harvesting apparatuscomprising: an insertion section to be inserted into a body cavity; agas supplying path for supplying a predetermined gas from an externalgas supplying device into the insertion section; an opening partprovided on the insertion section, the opening part discharging, throughthe insertion section, the predetermined gas supplied through the gassupplying path, into the body cavity; and a relief valve provided to thegas supplying path for maintaining pressure in the body cavity at apredetermined value.